如何在main中使用方法变量？

Question

对于我的学校，我需要创建一种方法，使虫子向任何方向移动。我有以下代码：

package Test;

//imports
import java.util.Scanner;
import java.util.Random;

public class test {
    public static void main(String[] args) {
        Scanner reader = new Scanner(System.in);
        ABug[] BugObj = new ABug[4]; //Creating object BugObj of class ABug
        int loop = 1;
        int i = 0;
        do {
            BugObj[i] = new ABug();  //creating instance
            System.out.println("Please enter the name of the bug:");   
            BugObj[i].name = reader.next(); 
            System.out.println("Please enter the species of the bug:");   
            BugObj[i].species = reader.next(); 
            System.out.println("Please enter the horizontal position of the bug:");   
            BugObj[i].horpos = reader.nextInt();
            System.out.println("Please enter the vertical postion of the bug:");   
            BugObj[i].vertpos = reader.nextInt();   

            System.out.println("_______________ Bug " +(+i+1) + " _______________\n" );
            System.out.println("Name: " + BugObj[i].name);           //Printing bug information out
            System.out.println("Species: " + BugObj[i].species);
            System.out.println("Horizontal Position: " + BugObj[i].horpos);
            System.out.println("Vertical Postion: " + BugObj[i].vertpos + "\n\n");
            move();

            i++;
            System.out.println("Would you like to enter another bug? \n 0-No,  1-Yes\n");
            loop = reader.nextInt();
        } while(loop == 1);
    }

    public static void move() {
        Scanner reader = new Scanner(System.in);
        System.out.println("Would you like this bug to move?\n 0-No,  1-Yes\n");
        if (reader.nextInt() == 0) {
            System.exit(0);
        }
        int r = (int) (Math.random() * (2- -2)) + -2;
        System.out.println(r);
    }
}

class ABug {                 //ABug class
    int horpos, vertpos, energy, id;
    char symbol;
    String species, name;
}

基本上我需要做的就是将错误位置的值与方法中生成的随机数一起使用。我是 java 的新手，我不确定该怎么做，甚至不知道该怎么做。

Answer 1

由于在 java 中对象是通过引用传递的，您只需将 ABug 对象传递给移动函数并更改 horpos、vertpos 属性即可。所以

move(BugObj[i]);

和

public static void move(ABug bug){
        Scanner reader = new Scanner(System.in);
        System.out.println("Would you like this bug to move?\n 0-No,  1-Yes\n");
        if (reader.nextInt() == 0)
        {
            System.exit(0);
        }

        int r = (int) (Math.random() * (2- -2)) + -2;

        int originalHorpos = bug.horpos

        int originalVertpos = bug.vertpos

        // Now just change the attributes however you see fit. i am just adding r
        bug.horpos = originalHorpos + r;

        bug.vertpos = originalVertpos + r

        /*by the way, we dont need to use variables for the original values. something like this would also work 

           bug.horpos += r; 
           bug.vertpos += r;

 i just want to explain that in java when you pass objects, they are passed by reference and hence you have access to all of its members.

*/
        System.out.println(r);


    }

另外，您不需要在移动函数中再次声明 Scanner 对象。您也可以将其传递给移动函数，然后根据需要多次阅读。

如何在main中使用方法变量？

How to use method variables in main?

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